ANS:B - out-fall sewer

The sewer which transports the sewage to the point of treatment is called the out-fall sewer. Out-fall sewers are large sewer lines that collect sewage from various smaller sewers, branches, and lateral lines within a sewerage network and transport it to treatment facilities or discharge points, such as wastewater treatment plants, outfalls into natural water bodies, or other disposal locations. So, the correct option is: out-fall sewer.